1. Field of the Invention
The present invention relates to measuring fluid flow. In particular, embodiments of the invention relate to measuring fluid flow in pipes.
2. Description of the Related Technology
There are many environments where information regarding the mass and/or volume flow rate of a fluid through a conduit is valuable. These include irrigation, residential water distribution, sewage treatment, and many others. Measuring fluid flow speed in pipes may be performed using a variety of sensing techniques. Although various types of mechanical flow meters have been used, acoustic methods are often preferable because of their ease of installation, lack of interference with the flow, and long term reliability. One type of acoustic flow measurement device utilizes the Doppler effect to measure flow speed. With these devices, sound energy is reflected off of particles moving with the flowing fluid and is received by a receiving transducer. Sound energy received by the receiving transducer is frequency shifted due to the relative motion between the particles and the receiving transducer. The frequency shift is related to the flow rate of the fluid.
Typically, these techniques involve a sensor installed within the pipe which measures the actual fluid speed at some point(s), along with the level of the fluid above the sensor and applies a numerical model to estimate total flow or Q. A limitation of many of the current pipe flow measurement techniques is that the sensor and its interconnect cable disturb the flow is being measured. Thus, a need exists for improved systems and methods of measuring fluid flow in pipes.